Boiler
Closed burning appliance designed to transfer heat from combustion to water or air which in turn is used for heating remote
parts of dwelling - can burn any fuel.

Bressemer
The bressemer is the large timber or stone that form the top of an inglenook fireplace.

Carbon Monoxide
Carbon Monoxide is almost always found in the exhaust gases of burning appliances. It is the result of restricted combustion.
The gas is highly toxic and inhibits the blood's capacity to carry life-sustaining oxygen to our brains and muscles. The symptoms
starting with shortness of breath, mild headaches and nausea, can lead to unconsciousness and death.

Chimney
A chimney is a structural column of masonry, including a number of flues.

Chimney Fan
An electrical unit that is fitted to the top of a chimney to overcome a lack of updraught cause by a flue that is too small,
or restricted in height. Will not necessarily overcome the inadequacies of a poor fireplace design.

Chimney Stack
The chimneystack is the freestanding section of the chimney, above the roofline. Being exposed to the elements as is the part most
liable to wear and tear. The wealthier the owner the more elaborate the chimneystack.

Chimney pot
The chimney pot was originally a decorative terminal to the chimney and the degree of ornateness reflected the wealth of the owner
(see Hampton Court Palace (London). Many early chimneys would have been built without chimney pots, which only became fashionable
in the mid 19th century.

Cowls
There are many types of cowls and they serve several functions.

to keep the rain out of the chimney

to keep birds out of the chimney

Test have shown that the effectiveness of cowls to increase the up-draught and to eliminate downdraft is very limited and unless the
cause of the problem is known, the appropriate cowl cannot be selected.

Flaunching
The flaunching is the weatherproof top of a masonry chimney (often concrete) which sheds the rainwater off the top. It is also used to
secure the chimney pots.

Flue
Separate compartment within a chimney. A chimney may have several flues. Every fireplace (and/or appliance) should have its own flue
within the chimney. Each flue should be gas tight.

Gather
The gather is located above the open fire, and (as its name implies) gathers the smoke into the flue.

Inglenook
A very large traditional open fire in which the fire was continually burning on the hearth, which formed the prime heat source in the
house as well as the place for cooking. The flue from the inglenook was un- throated and possibly 80% of the heat was lost up the flue.

Mid-feathers/Withers
The traditional chimney is divided into the various flues with mid feathers built of brick, stone, or slate. The mid-feathers are often
the first unit in the chimney to fail as generally they are not tied in to the rest of the chimney structure and will collapse.

Parging (pargetting)
Because it was always very difficult to ensure that masonry was gas tight, the mason parged or rendered the flues using a traditional
mixture of cow dung and lime. This was more recently replaced by a lime/cement/sand mix, which has itself been replaced by the requirement
for all flues to be lined in new buildings in the UK from 1965 onwards.

Register plate
Used where a stove or boiler is installed into a traditional chimney. It is the closing plate installed at the base of the flue
registering the position of the flue pipe. It prevents heat loss up the flue and air from the room being drawn up the flue. It
should be gas tight.

Soot door/Sweeping hatch
The access door into the flue for sweeping, also known as a sweeping hatch. Should be located to allow any debris falling down the chimney
to be removed.

Stove
Closed burning appliance designed for local space heating - can burn any fuel.

Throat
The throat is located immediately above the opening of fireplace. It is designed to restrict the heat loss up the flue.
In sophisticated designs the throat can incorporate a damper mechanism to adjust the area to best suit the circumstances
of that time (e.g. to close it completely when not in use).